With API settings turned off my button no longer works?

Hello,

When I have the API button the button to rent our movie no longer works and goes to PayPal?
http://geneticroulettemovie.com/rentgrm/

Do I have to allow Accept API Logins for a daily pass?

What steps am I missing? If I turn Accept API Logins off the button works and goes to our PayPal checkout page?

Thank you!